1. Field of the Invention
The present invention relates to a device for lubricating an oil seal which performs sealing of a gear room of an engine against oil leakage to the outside of the engine by contacting a side face of a disk plate fixed to a crankshaft of a diesel engine.
2. Description of the Related Art
In some high speed diesel engines, a disk plate is fixed to an end of the crankshaft, an oil seal of flat surface sealing type is provided to contact a side face of the disk plate, and a gear room of the crankshaft end side is sealed against oil leakage to the outside with the oil seal of flat surface sealing type.
In such an engine, in order to prevent oil leakage from the oil seal due to overheating of the oil seal contacting the side face of the disk plate which is fixed to the crankshaft and rotates at high speed, the oil seal is cooled by oil drops falling down onto the slide contacting part of the oil seal in the gear room.
A device for lubricating an oil seal of an engine is disclosed in Japanese Laid-Open Patent Application No. 2000-282828A.
In the art disclosed in JP2000-282828A, an oil seal contacting the outer circumference of the hub of a crank pulley is attached to a timing chain cover in which an oil pump is integrated, a pressure regulating valve is provided to the oil pump, a portion of the oil released to regulate oil pressure is introduced to a hole provided in the chain cover to be supplied to the slide contacting part of the oil seal. Thus, by supplying oil positively to the slide contacting part of the oil seal, to which conventional oil leaked from the oil pump was utilized for lubrication of the oil seal, lubrication of the oil seal is improved and occurrence of oil leaks due to wear of the oil seal lip is prevented.
Conventionally, air born droplets in the gear room or oil which falls down along the wall of the gear case is utilized to cool and lubricate the slide contacting part of the oil seal, so a sufficient amount of oil can not be supplied to cool and lubricate the slide contacting part of the oil seal particularly in the case of a high speed engine in which the sliding speed at the slide contacting part is very high, and overheating of the oil seal due to a shortage in oil supply tends to occur.
With the art disclosed in JP2000-282828A, a part of the oil released to regulate oil pressure is supplied to the slide contacting part of the oil seal and overheating of the oil seal and occurrences of damage in the oil seal due to a shortage in oil supply can be prevented; however, oil supplied to the slide contacting part of the oil seal is a portion of the oil released to regulate oil pressure, so it is difficult to be assured that the proper amount of oil is always introduced to the slide contacting part of the oil seal, and when excessive oil is supplied, oil leakage may occur.